1. Field of Disclosure
The present disclosure relates to batteries and, more particularly, to an apparatus for measuring current flow to and from a terminal post of a battery.
2. Related Art
The present disclosure is described in conjunction with a lead-acid battery of the type used to provide starting power in vehicles, such as automobiles, trucks and motorcycles. This type of battery generally includes a plastic casing containing positive and negative lead plates immersed in an acid electrolyte. The plates are separated by non-conductive sheets, and a positive lead strap connects the positive plates while a negative lead strap connects the negative plates. Lead posts are connected to each strap and extend through the casing, and lead positive and negative battery terminals are secured to the ends of the posts outside the casing for receiving cable connectors.
Presently, means for monitoring the status of batteries normally measures the voltage provided between the battery terminals. However, battery voltage in itself provides limited information as to battery status and performance. What is desired instead is an apparatus for monitoring the flow of current into and out of the battery. The current flow can then be used over time to calculate and monitor the level of charge of the battery. Preferably, the apparatus will be simple in design, and easily incorporated in a battery.
In response, the present disclosure provides an apparatus for measuring electrical energy passing to and from a battery post. The apparatus includes a resistor for providing an electrical connection to a battery post, and the resistor has a known resistance, a first conducting surface and a second conducting surface. The conducting surfaces are arranged such that current flow from the post will travel through the resistor from the first conducting surface to the second conducting surface, and current flow to the post travels through the resistor from the second to the first conducting surfaces. The energy measuring apparatus further includes a first lead electrically connected to the first conducting surface of the resistor, and a second lead electrically connected to the second conducting surface of the resistor.
According to one aspect of the present disclosure, the apparatus further includes a volt meter connected between the first and the second leads for measuring a voltage drop across the resistor.
According to another aspect, the apparatus further includes a computer having memory for storing the known resistance of the resistor, and a processor programmed to receive the measured voltage drop from the volt meter, retrieve the known resistance from the memory, and calculate current flow through the resistor based on the measured voltage drop and the known resistance.
The present disclosure also provides a battery including the measuring apparatus, and further including a case, a storage cell contained within the case for receiving and storing an electrical charge, and an electrically conductive post connected to the storage cell and extending out of the case. The first conducting surface of the resistor is positioned on a portion of the post extending out of the case.
According to an aspect of the present disclosure, the storage cell of the battery includes lead and lead-oxide plates immersed in an acid electrolyte.
These and other aspects of the present disclosure will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.